The internet is undergoing one of its biggest infrastructure changes in decades: the transition from IPv4 to IPv6. If you have noticed longer, more complex IP addresses showing up in logs or network settings, that is IPv6. Here is what you need to know.
IPv4: The Original IP Address System
IPv4 (Internet Protocol version 4) has been the backbone of the internet since 1983. An IPv4 address looks like this: 192.168.1.1. It uses 32 bits, which allows for about 4.3 billion unique addresses.
That seemed like plenty in the 1980s, but with billions of smartphones, laptops, IoT devices, and servers now connected to the internet, we have essentially run out of IPv4 addresses. The last blocks were allocated by regional internet registries years ago.
IPv6: The Next Generation
IPv6 (Internet Protocol version 6) was designed to solve the address shortage. An IPv6 address looks like this: 2001:0db8:85a3:0000:0000:8a2e:0370:7334. It uses 128 bits, providing approximately 340 undecillion (3.4 x 1038) unique addresses.
Key Differences Between IPv4 and IPv6
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Address format | Dotted decimal (192.168.1.1) | Hexadecimal (2001:db8::1) |
| Total addresses | ~4.3 billion | ~340 undecillion |
| NAT required | Yes (common) | No (every device gets a public address) |
| Built-in security | Optional (IPsec) | Mandatory (IPsec) |
| Header complexity | Variable length | Fixed, simplified |
For a more detailed comparison, see our IPv4 vs IPv6 guide.
How Does IPv6 Affect You?
Privacy Implications
With IPv4 and NAT (Network Address Translation), multiple devices in your household share a single public IP. With IPv6, each device can have its own unique public address, which could make individual device tracking easier.
Modern operating systems mitigate this with temporary IPv6 addresses that change periodically, but it is worth being aware of. Learn more in our online privacy guide.
Performance
IPv6 can be slightly faster than IPv4 in some scenarios because it eliminates the overhead of NAT translation and has a simplified packet header. Many content delivery networks (CDNs) now prioritize IPv6 connections.
Compatibility
Most modern devices and operating systems fully support IPv6. However, some older routers, firewalls, and applications may not. During the transition period, most networks run both IPv4 and IPv6 simultaneously (called "dual-stack").
How to Check if You Have IPv6
Visit WheresThatIP.com — we detect and display both your IPv4 and IPv6 addresses if available. You can also check in your device's network settings or run:
curl -6 https://www.wheresthatip.com/ipThe Current State of IPv6 Adoption
As of 2026, global IPv6 adoption is around 40-45%, with some countries leading the way:
- India — ~70% adoption, driven by mobile carriers like Jio
- United States — ~50% adoption, led by major carriers
- Germany — ~60% adoption
- China — Growing rapidly with government mandates
Major services like Google, Facebook, Netflix, and most CDNs fully support IPv6.
Do You Need to Do Anything?
For most users, the transition is automatic. Your ISP and device handle IPv6 behind the scenes. However, if you are a network administrator or developer, you should:
- Ensure your infrastructure supports IPv6
- Test applications with IPv6 addresses
- Update firewall rules to cover IPv6
- Use our DNS lookup tool to verify AAAA records for your domains
The transition from IPv4 to IPv6 is inevitable. While it is happening gradually, understanding the basics helps you make informed decisions about your network and privacy.